Connectors with a large number of signal terminals are typically used for the connection of complex circuit boards, in which case the connectors may have a modular structure in order to achieve a high degree of variability. Such connectors are used, for example, in service cabinets, in order to connect a large motherboard to a large number of parallel circuit boards.
Particularly in the case of electrical connectors such as these, there is an ever-present demand to increase the number of terminals in each connector, and to reduce the size of the connectors. These objectives are, however, partially contradictory for typical signal frequencies in the region of several GHz.
A modular connector with a metal bracket is known from the document US 2002/0111,068. However, this connector is subject to the risk of the metal bracket touching conductors of adjacent circuit boards when one circuit boards is being inserted between adjacent circuit boards, thus producing a short-circuit. Furthermore, the connector is not very robust and is difficult to assemble.
In the course of the desire to increase the maximum signal frequency, the connectors have typically been provided with a shield to prevent electromagnetic crosstalk. As the frequencies become ever higher, this shield is also subject to continuous pressure for improvement.
For example, a modular connector with a multi-contact ground shield is known from the document U.S. Pat. No. 6,347,962. However, two ground contacts are closed for each ground contact pair when connected to a mating male connector. In this connector, the first contact is used as a leading ground contact or provides an electrostatic discharge (ESD), that is to say it acts as so-called ESD protection. However, the double contact reduces the normal force in particular on the second contact, and this has a disadvantageous effect on contact reliability. A further disadvantage is that a high operating force is required due to the coefficient of friction. Furthermore, the connector has a fixed plug face, and is thus difficult to manufacture and is inflexible.